docstr: Start one PaddleHub-Serving instance by arguments with flask.
docstr_tok: ["Start","one","PaddleHub-Serving","instance","by","arguments","with","flask","."]
code: def start_single_app_with_args(self):
      """
      Start one PaddleHub-Serving instance by arguments with flask.
      """
      module = self.modules_info
      if module is not None:
          port = self.args.port
          if is_port_occupied("127.0.0.1", port) is True:
              log.logger.error(
                  "Port %s is occupied, please change it." % port
              )
              return False
          self.preinstall_modules()
          self.dump_pid_file()
          app.run(configs=self.modules_info, port=port)
      else:
          log.logger.error("Lack of necessary parameters!")
  
imports: import argparse
  import os
  import platform
  import json
  import multiprocessing
  import time
  import signal
  import paddlehub
  from paddlehub.commands import register
  from paddlehub.serving import app_compat
  from paddlehub.env import CONF_HOME
  from paddlehub.serving.http_server import run_all, StandaloneApplication
  from paddlehub.utils import log
  from paddlehub.utils.utils import is_port_occupied
  from paddlehub.server.server import CacheUpdater
label_desc: Use image node_id 8 for calling the ServingCommand obj's underlying member method code with example usage: obj.start_single_app_with_args() and returns: False